Interpretive Summary: There is a need to better understand the exchange of water, mass and energy between the northern boreal forests and the global atmosphere and biosphere. The boreal forest is believed to play a critical role in the global carbon cycle, and is believed to be especially vulnerable to the effects of global change. An international, interdisciplinary project called the Boreal Ecosystem Atmosphere Study (BOREAS) was conducted at two Canadian boreal forest locations. Remote sensing was crucial to the planning, modeling, and analyses. Innovative remote sensing methods expanded our understanding of the boreal forest in four key areas: 1) vegetation structure, 2) land cover classification, 3) carbon balance, and 4) links between surface properties, weather and climate. A considerable amount of scientific literature and a well-documented, publicly available database have resulted from the study. These provide a lasting scientific resource, and opportunities to further advance knowledge of this critical northern biome.

Technical Abstract:
The Boreal Ecosystem Atmosphere Study (BOREAS) was a large, multi-year internationally-supported study designed to improve our understanding of the boreal forest biome and its interactions with the atmosphere, biosphere and the carbon cycle in the face of global climate change. In the initial phase of this study (early 1990's), remote sensing played a key role by providing products needed for planning and modeling. During and after the main BOREAS field campaigns (1994 and 1996) innovative remote sensing approaches and analyses expanded our understanding of the boreal forest in four key areas: 1) definition of vegetation structure, 2) land cover classification, 3) assessment of the carbon balance, and 4) links between surface properties, weather and climate. In addition to 6 BOREAS special issues and over 500 journal papers, a principal legacy of BOREAS is its well-documented and publicly available database, which provides a lasting scientific resource and opportunity to further advance our understanding of this critical northern biome.